<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>按从大到小排序</title>
</head>
<body>
<script>
    var arr = [70, 67, 49, 35, 59, 98, 100, 20];

    var len = arr.length;
    for (var i = 0; i < len - 1; i++) {
        for (var j = 0; j < len - 1 - i; j++) {
            if (arr[j] < arr[j + 1]) {
                var temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
        }
    }
    document.write(arr.join(","));
</script>
</body>
</html>